Modulation mode and communication circuit based on mobile phone audio interface and communication method of communication circuit based on mobile phone audio interface

Abstract

The invention discloses a communication circuit based on a mobile phone audio interface. The communication circuit comprises an MCU and a communication processing unit, and can be directly connected with the mobile phone audio interface through a connector, and used devices only include a comparator, an electronic switch, several resistors and several capacitors besides the MCU. Due to the use of the electronic switch, the communication processing unit imitates the mode of a headset for working, and the compatibility between a communication unit and a mobile phone is guaranteed in hardware. In addition, the invention discloses a communication method of the communication circuit. The communication method specifically includes the steps of data frame packing and unpacking, signal coding and decoding and signal inputting and outputting. Particularly, in order to achieve the communication compatibility caused by the difference of hardware circuits inside audio interfaces of different mobile phones, a simple and reliable waveform recovery algorithm is proposed and used, ideal signals are recovered according to signal features, and the communication accuracy and the communication stability are greatly improved.

Description

technical field [0001] The invention belongs to the technical field of communication, and in particular relates to a modulation mode based on an audio interface of a mobile phone, a communication circuit and a communication method thereof. Background technique [0002] With the rapid development of computer technology, the smart features of mobile phones are getting higher and higher, making mobile phones widely used by people, and has become one of the most common devices in people's carry-on devices. With the development of cloud computing, cloud storage and other technologies, mobile phones, as devices connected to the cloud, play an increasingly important role in people's daily life, bringing great convenience to people's lives. [0003] The performance improvement of mobile phones is very obvious, so that more and more applications are developed based on mobile phones, and the form of Internet of Things with mobile phones as the core bridging external devices is becomin...

AI Technical Summary

Problems solved by technology

The audio interface of the mobile phone is used for audio equipment. It is an analog channel, that is, as an analog signal transmission channel. Therefore, many designs use frequency modulation to communicate through the audio interface. When decoding mobile phones to identify different frequencies, FFT (Fast Fourier) is often used. Transformation, fast Fourier transform) or autocorrelation method, this method needs to obtain a piece of data before starting the calculation, the calculation amount is large, the mobile phone load is heavy, and the real-time performance is not good enough

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